The present invention relates to a connector for establishing electric and mechanical connections between two circuit supports or between a circuit support and a component such as a display cell, and more particularly to a novel structure of a connector with a flexible circuit support.
There are two representative examples of the prior art connector for use with a flexible circuit support bearing a desired circuit wiring pattern.
1. A multi-pin connector is secured at one end of a flexible circuit support bearing a desired circuit wiring pattern and another circuit board whether flexible or rigid is plugged into the multi-pin connector, as seen from FIG. 1. In FIG. 1, a multi-pin connector plug 3 is provided at both ends or terminal regions of a flexible circuit support 1 bearing a desired circuit pattern 2. The connector plug 3 has a predetermined number of apertures for reception of a printed circuit board 5 with limited contact regions 6.
2. Both ends of circuit wiring leads are adapted to extend from the edges of a flexible circuit support, the extensions of these conducting leads being bonded directly to limited terminal regions of another support by soldering. This is illustrated in FIG. 2. In FIG. 2(a), a flexible circuit support 7 carries a predetermined number of conducting leads 8 which have extensions 9 and 10 at the both ends thereof extending beyond the edges 11 and 12 of the flexible circuit support 7. As viewed from a cross sectional view of FIG. 2(b), the extensions of the conducting leads are located into an aperture 14 formed in another circuit board 13 due to be connected to the flexible support 7 and soldered as denoted 15 to complete connections between the terminals 9 and 16.
Nevertheless, the first named type of connector is undesirable because it is voluminous, physically complicated and very expensive. In case of the second type of connector, a limit is placed upon the material of the flexible circuit support in addition to the laborious soldering process. In other words, only those materials which can tolerate a high temperature during the soldering process can be used, for example, polyimide and polyamide. It is difficult to find a flexible circuit support of comparatively low heat resistance.
It is therefore an object of the present invention to provide a novel connector which overcomes the problems with the prior art connectors. To achieve the above described object, an electrically conducting hot melt adhesive is interposed between a limited electrical contact region of a circuit pattern bearing a flexible circuit support and the counterpart of a circuit support or a component. By heating and subsequently cooling the electrically conducting hot melt adhesive the limited contact regions are adhesively bonded and connected together. To enhance the strength of the electrical and physical connections, it is preferable that an electically nonconducting hot melt adhesive be interposed at non-electrical contact regions not far from the electrical contact regions. Conventional hot melt adhesives will show electrical conductivity when containing conducting particles such as carbon distributed therethrough.